John Deere Engines SPN676FMI14 Fault Code: Cold Start Aid Relay Signal Not Received When Expected
Cold Start Aid Relay Signal Not Received When Expected · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 676 FMI 14 means the John Deere ECU commanded the cold start aid relay ON but did not see it energize. The code stores when the ECU turns the relay back OFF, about 15 seconds after commanding it ON. It is logged as a Warning and mainly affects cold-weather starting.
Medium severity. This is logged as a Warning-level code, not an engine-protection shutdown. The real-world risk is a hard or failed cold start in low ambient temperatures, so it should be diagnosed before the next cold start rather than ignored, but it does not demand an immediate stop of a running engine.
What does John Deere Engines error code SPN676FMI14 mean?
SPN 676 FMI 14 is set by the engine ECU when it sends battery voltage to energize the cold start aid relay (identified as K5803 in the wiring) but does not get back the feedback signal confirming that the relay actually energized. In plain terms, the computer flipped the switch for the cold start aid but never saw proof the switch turned on.
The cold start aid relay controls a heating function (such as an intake air or ether-assist type circuit depending on the engine) that helps the engine start in cold ambient temperatures. On some versions, the ECU decides whether to energize this relay based on manifold air temperature. If the relay does not respond when commanded, that assist is not available, which shows up as harder starting or a longer crank time in cold weather.
Because the ECU only commands the relay ON for a short window before commanding it OFF again, this fault is often only visible as a stored code rather than an active one. The failure event is brief, but the underlying wiring or relay problem is very much still there.
What triggers a John Deere Engines SPN676FMI14 code?
The ECU sets this code when it commands the cold start aid relay ON and detects the relay output is low instead of energized. The code becomes stored when the ECU then commands the relay OFF, approximately 15 seconds after the ON command was given. Because that active window is so short, the code usually shows up in the stored fault list rather than as an active fault on the display.
Common causes of SPN676FMI14
- Cold start aid fuse (identified as F5013 or F5005 depending on the machine/engine build) is open, or there is an open circuit somewhere in the 12-volt supply feeding the relay.
- The cold start relay (K5803) is disconnected, has failed internally with an open circuit, or is simply bad.
- A short to ground on the feedback wire running from the relay back to the ECU, which prevents the ECU from ever seeing a valid 'relay energized' signal even if the relay itself is fine.
- Bad or corroded terminals or connector pins at the cold start relay connector itself.
- Bad or corroded terminals or connector pins at the X5004 connector.
- Bad or corroded terminals or connector pins at the ECU connector.
- General open or short conditions in the wiring harness between the ECU, the fuse, the relay, and the feedback path.
How to troubleshoot John Deere Engines SPN676FMI14: first checks
- Pull up stored and active codes and check for SPN 676 FMI 5 or SPN 676 FMI 6 alongside FMI 14. These are listed as part of the same troubleshooting sequence and can point to whether the issue is a full open circuit, a different electrical fault mode, or the feedback-specific problem covered by FMI 14.
- Inspect the cold start aid fuse (F5013 or F5005 depending on engine) for continuity or visible damage, and check the 12-volt supply circuit feeding the relay for an open condition.
- Visually inspect the cold start relay (K5803) connector and the X5004 connector for corrosion, bent pins, or loose terminals. Many of these faults trace back to a bad connection rather than a bad part.
- Check the ECU connector terminals for the same kind of corrosion or looseness, since a poor ECU-side connection can mimic a bad relay.
- With the engine off and battery disconnected as appropriate, check the feedback wire between the relay and the ECU for a short to ground, since this alone can trigger the code even with a fully functional relay.
- If wiring and connectors check out, test or swap the cold start relay itself to rule out an internally open relay.
How the code clears
No separate clearing step is listed beyond correcting the wiring, connector, fuse, or relay fault. Once the underlying open circuit, short to ground, or bad relay is repaired, the ECU should stop detecting the missing feedback signal on the next cold start attempt where the relay is commanded. Follow the listed troubleshooting sequence (checking SPN 676 FMI 5 and FMI 6 first) to make sure a related fault isn't masking the real problem before considering the repair complete.
Frequently asked questions
What does SPN 676 FMI 14 mean on a John Deere engine?
It means the engine ECU turned on the cold start aid relay but did not receive confirmation that the relay actually energized. The ECU expected a feedback signal and did not get it.
Will SPN 676 FMI 14 stop my engine from running?
No. It is logged at a Warning alarm level. The ECU keeps trying to maintain normal operating conditions. The practical effect is that the engine may need extended start time or may not start well in low ambient temperatures, not that a running engine will shut down.
Why does this code only show up as stored and not active?
The ECU only commands the cold start aid relay ON briefly, then commands it OFF about 15 seconds later. Because the fault window is that short, it is common for the code to log only in the stored fault list rather than staying active on the display.
What parts should I check first for this code?
Start with the cold start aid fuse and the 12-volt supply circuit, then inspect the cold start relay (K5803) and its connector, the X5004 connector, and the ECU connector for corrosion or loose terminals. Also check the feedback wire for a short to ground.
Is the cold start relay always bad if I get this code?
Not necessarily. Possible causes include an open fuse, an open 12-volt supply circuit, a disconnected or internally open relay, or a short to ground on the feedback wire. Connector and terminal problems at several points in the circuit are also listed as common causes, so the relay itself is only one of several possibilities.
Does this code affect normal warm-weather starting?
The cold start aid function is mainly relevant in low ambient temperatures. In warmer conditions the engine may start normally even with this fault present, but the underlying wiring or relay issue should still be fixed before cold weather arrives.
What other codes should I check alongside SPN 676 FMI 14?
The listed troubleshooting sequence includes SPN 676 FMI 5 and SPN 676 FMI 6, and on some versions SPN 676 FMI 31, before addressing FMI 14. Checking these in order can help isolate whether the fault is a simple open circuit, a different fault mode, or specifically the missing relay feedback covered by FMI 14.